CELLS: Plants TEKS 7.13B- Describe and relate responses in organisms that may result from internal stimuli such as wilting in plants …that allow them to maintain balance TEKS 7.7C- Demonstrate and illustrate forces that affect motion in everyday life such as emergence of seedlings, turgor pressure, and geotropism

PLANT CELLS: Vacuole A vacuole is a membrane-bound sac found in plant and animal cells. Vacuoles tend to be large in plant cells and play several roles: storing nutrients and waste products, helping increase cell size during growth, and even acting much like lysosomes of animal cells. The plant cell vacuole also regulates turgor pressure in the cell. Water collects in cell vacuoles, pressing outward against the cell wall and producing rigidity (stiffness) in the plant. Without sufficient water, turgor pressure drops and the plant wilts (droops)

ANIMATION http://www.kscience.co.uk/animations/turgor.htm

Reviving Celery Materials: wilted stalk of celery glass of water blue food coloring knife Procedure: Slice off a large piece of the bottom of the stalk of celery.  Put five drops of blue food coloring in the glass of water.  Place the celery in the water and let it stand overnight.

What’s your hypothesis? Record your observations in their science journals, and make a prediction about what you think will happen in a few days.

What happened? Slicing off the bottom off of the celery stalk made sure that none of the celery cells were not closed off of dried out.  The blue water then entered in the water-conducting tubes called xylem.  These tubes follow the whole length of the stalk of the celery.  Water leaves the xylem tubes and enters the cells up and down the celery stalk.  When you slightly bend a plant, you notice that it stands up straight again after you let go.  This is because every single plant cell is full of water.  The water makes each cell firm, and all the cells combined give the plant a rigid feeling.  A plant wilts when it doesn't get enough water.  The cells lose water and become limp.  Then, the plant droops.  The pressure of the water inside the vacuoles of the plant is called turgor pressure

The picture shows a turgor pressure demonstration using celery The picture shows a turgor pressure demonstration using celery. Place the pictures of the celery in order of least amount of pressure to the greatest amount of pressure. Q, R, S, T S, R, Q, T Q, R, T, S S, T, Q, R